Agriculture and Agri-Food Canada

About: Agriculture and Agri-Food Canada is a facility organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Soil water. The organization has 10921 authors who have published 21332 publications receiving 748193 citations. The organization is also known as: Department of Agriculture and Agri-Food.

Selenium in soils and crops, its deficiencies in livestock and humans: Implications for management

Abstract: Selenium (Se) content in soils varies greatly depending upon the parent rock, weathering and texture. In general, total soil Se of 0.1 to 0.6 mg kg‐1 is considered deficient. Selenium deficiency regions in New Zealand, Denmark and the Atlantic Region of Canada contain 0.1 to 0.6 mg Se kg‐1 in the soil. Soil acidity is an important factor resulting in decreased Se availability to crops. Selenium concentration in plants can range from 0.005 mg kg‐1 in deficient crops to about 5500 mg kg‐1 in Se accumulators on seleniferous soils. Among crops, brassicas and legumes, particularly soybeans, contain higher Se than other crops. Selenium is an essential mineral for livestock as well as for humans, but its essentiality for the growth of Se accumulators or non‐accumulators has so far not been demonstrated. Feed crops containing more than 0.1 mg Se kg‐1 will protect livestock from Se deficiency disorders. Inadequate Se in animal rations can cause White Muscle Disease in calves, sheep and goat; Exudative Dia...

Checklist of beetles (Coleoptera) of Canada and Alaska. Second edition

Abstract: All 8237 species-group taxa of Coleoptera known to occur in Canada and Alaska are recorded by province/territory or state, along with their author(s) and year of publication, in a classification framework. Only presence of taxa in each Canadian province or territory and Alaska is noted. Labrador is considered a distinct geographical entity. Adventive and Holarctic species-group taxa are indicated. References to pertinent identification keys are given under the corresponding supraspecific taxa in the data archive.

Identification of differentially regulated proteins in response to a compatible interaction between the pathogen Fusarium graminearum and its host, Triticum aestivum

Abstract: Using proteomic analyses, a study was carried out aimed at understanding the molecular mechanism of interaction between Fusarium graminearum and Triticum aestivum. Wheat spikelets were inoculated with H2O and conidia spores of F. graminearum. Proteins were extracted from spikelets harvested at three time points: 1, 2 and 3 days post inoculation. About 1380 protein spots were displayed on 2-D gels stained with Sypro Ruby. In total, 41 proteins were detected to be differentially regulated due to F. graminearum infection, and were analyzed with LC-MS/MS for their identification. The proteins involved in the antioxidant and jasmonic acid signaling pathways, pathogenesis-related response, amino acid synthesis and nitrogen metabolism were up-regulated, while those related to photosynthesis were less abundant following F. graminearum infection. The DNA-damage inducible protein was found to be induced and glycosylated in F. graminearum-infected spikelets. Using TargetP program, seven of the identified wheat proteins were predicted to be located in the chloroplast, implying that the chloroplast is the organelle mostly affected by F. graminearum infection. Eight identified fungal proteins possess possible functions such as antioxidant and acquiring carbon from wheat through glycolysis in a compatible interaction between F. graminearum and wheat.

In vitro effects of steroidal saponins from Yucca schidigera extract on rumen microbial protein synthesis and ruminal fermentation

Abstract: In a first experiment, ground alfalfa hay and rolled barley grain were incubated in buffered ruminal fluid with and without Yucca schidigera extract (YE, 0 or 10 mg ml−1). Gas and total VFA production from barley grain were increased (P < 0.05) by YE during the first 10 h of incubation; from alfalfa hay, these were reduced (P < 0.001) throughout the 24 h. Yucca extract reduced (P < 0.001) acetate/propionate ratios and ammonia concentrations, irrespective of substrate. In a second experiment, ground barley grain was incubated in a buffered suspension of mixed ruminal microbes obtained by low-speed centrifugation of ruminal fluid. Steroidal saponins (SAP) isolated from YE were included at 0, 15, 75 or 225 µg ml−1. Microbial incorporation of 15N was increased (P < 0.05) by 15 µg SAP ml−1 but decreased (P < 0.05) by 225 µg SAP ml−1. Gas and VFA production peaked with 75 µg SAP ml−1 and were elevated (P < 0.05) relative to control in the presence of 75 µg SAP ml−1. Microbial protein synthesis was increased (P < 0.05) by SAP at 15 µg ml−1 and reduced (P < 0.05) by the higher concentrations. Acetate/propionate ratios were linearly reduced by SAP from 8 to 24 h incubation (P < 0.01). The effects of SAP on digestive microbes were less pronounced (P < 0.05) with barley grain digestion than with alfalfa. A YE × diet interaction was recorded. The biological activity of YE was shown to be attributable to its SAP and to be diet-dependent. © 2000 Society of Chemical Industry. Contributions of Y Wang, T A McAllister, L J Yanke and Z Xu © Minister of Public Works and Government Services Canada 2000